diff --git a/themes/new_darcula.json b/themes/new_darcula.json
index be6c2ed..4830269 100644
--- a/themes/new_darcula.json
+++ b/themes/new_darcula.json
@@ -402,6 +402,7 @@
         "punctuation.accessor",
         "keyword.operator",
         "keyword.other.unit.percentage",
+        "keyword.other.back-reference.regexp",
         "punctuation.definition.entity",
         "punctuation.separator.key-value",
         "punctuation.separator.list.comma.css",
diff --git a/themes/new_dark.json b/themes/new_dark.json
index 0a987bd..bf1a98c 100644
--- a/themes/new_dark.json
+++ b/themes/new_dark.json
@@ -410,6 +410,7 @@
         "punctuation.accessor",
         "keyword.operator",
         "keyword.other.unit.percentage",
+        "keyword.other.back-reference.regexp",
         "punctuation.definition.entity",
         "punctuation.separator.key-value",
         "punctuation.separator.list.comma.css",